[webrequest] introduce an alternative implementation using the repoapi DBAPI specific parts of ``CubicWebRequestBase`` are extracted in a ``DBAPICubicWebRequestBase`` decicated class and a new ``ConnectionCubicWebRequestBase`` is introduced that provide the same services but using a repoapi.ClientConnection as data source. For now the ``DBAPICubicWebRequestBase`` is still used by default.

/***************************************/
/* Manage view (views/startup.py)      */
/***************************************/

table.startup {
  width: 100%;
}

/* table.startup td { */
/*   padding: 0.1em 0.2em; */
/* } */

table.startup td.addcol {
  text-align: right;
  width: 0.5em;
}

table.startup th{
  text-align: left;
}